Oryctus sps

The Oryctes rhinoceros virus is a pathogenic virus of invertebrates, infecting a number of coleopteran insects in the family Scarabaeidae. The mature virion of Oryctes rhinoceros virus consists of an enveloped, rod-shaped nucleocapsid and contains a uniqu e tail-like structure protruding from one end. The mature virion is produced by virus budding from the plasma membrane and contains two unit membranes. The genome is a single supercoiled circular dsDNA of approximately 130 kbp. Although these viruses we re previously classified as members of the family Baculoviridae , they differ in several respects including virion morphology and the lack of an occlusion body.

Virions have a complex construction and consist of an envelope and a nucleocapsid. During their life cycle, virions have an extracellular transcription phase; can occur in two phenotypes. The infection is initiated by extracellular virions in the gut epithelium (phenotype I) and phenotype II virions generated when the nucleocapsids bud through the plasma membrane at the surface of infected cells (termed budded virions or BV). Virus may be sequestered within inclusion bodies which are occluded by protein bodies, by a crystalline protein matrix, or are not occluded and typically contain one nucleocapsid composed of a single viral protein, polyhedrin, or granulin. Virus initiating infection is occluded by a crystalline protein matrix of polyhedral or ovicylindrical shape. Each occlusion body measures 0.13-15 μm and contains one or several virions. Virions in occlusions consist of a single (S) or multiple nucleocapsids (M) within a single viral envelope. Virions are enveloped. Virions are rod-shaped. A cell-associated virus, second phenotype, is generated when the nucleocapsid buds through the plasma membrane at the surface of infected cells. BVs typically contain a single nucleocapsid, or is needed if infection is not restricted to the gut epithelium cells. The secondary infected tissue produces occluded virions (ODV). Intracellular virions are enveloped with a loose fitting membrane. The envelope surrounds one or two nucleocapsids to several nucleocapsids and has terminal surface projections. The surface projections are peplomers composed of one type of protein. The surface projection proteins are glycosylated. Capsid/nucleocapsid is elongated and exhibits helical symmetry. The nucleocapsid is rod-shaped; has a length of 200-450 nm; 30-100 nm in diameter. Capsid electron dense.